No brakes in the morning. It will definitely wake you up more than coffee.

[WyrTwister]

Just used Paint .

A PVC valve is suppose to all a specific amount of air ( and fumes ) to be sucked from the engine and burned . That way it is not just vented to the atmosphere . They usually rattle when you shake them . But , as inexpensive as they are , if in doubt , replace .

I have the impression the new vacuum booster is behaving the same as the old one ?

Just wondering what the ID of the new vacuum hose to the booster is ? And if you can find an inline check valve to fit ?

My late Dad had a Ford LTD we put an after marker cruse control on . The car was geared high and when climbing a long steep hill , the cruse control would not hold speed .

In those days , the cruse control was electrical / vacuum . What was happening was , as the cruse opened the throttle , manifold vacuum would fall . It would reach the point where vacuum dropped to the point where there was not enough vacuum to operate the vacuum servo , to open the throttle any more , to maintain speed up the hill .

I did one or both of 2 things . Added a vacuum reservoir or added a check valve in the line connecting the system to the intake manifold . This solved the issue .

But that vacuum hose was maybe 1/4" ID . Looks like your hose to the booster is more like 1/2" ? Not sure you can find a check valve that large . For an acceptable cost ?

God bless
Wyr

PS When I was working on our 91 Caprice , I received a rewards card in the mail , from O'Reilly Auto Parts do something like $ 5 .